1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method for forming a film such as an interlayer insulating film on a substrate such as a semiconductor wafer.
2. Description of the Related Art
In the manufacturing process of a semiconductor device, known as one of the methods for forming a dielectric film such as an interlayer insulating film on a semiconductor wafer is a method of spin-coating a semiconductor wafer with a coating liquid by using an SOD (spin on dielectric) system, followed by applying a physical treatment such as heating to the coated liquid.
In recent years, a material having a low dielectric constant is required as a material of the interlayer insulating film and, thus, various materials, i.e., so-called xe2x80x9clow-k materialsxe2x80x9d, are being developed. Some of these low-k materials are required to be subjected to a heat treatment with a gas containing a prescribed amount of a water vapor.
FIG. 1 is a cross sectional view schematically showing the construction of a conventional heat treating unit 101 used for forming a dielectric film by using a low-k material requiring a heat treatment under a humidified atmosphere. As shown in the drawing, the heat treating unit 101 comprises a hot plate 102 on which a wafer W is disposed and a chamber 103 housing the hot plate 102 and the wafer W disposed on the hot plate 102. The chamber 103 consists of a lower vessel 103b and a lid 103a that can be lifted. A gas containing a prescribed amount of a water vapor is supplied into the chamber 103 through a gas supply port 104b formed in the bottom portion of the lower vessel 103b, with the result that the wafer W is exposed to the gaseous atmosphere. The gas supplied into the chamber 103 is exhausted to the outside through an exhaust port 104a formed in substantially the center of the lid 103a. Incidentally, a reference numeral 105 shown in FIG. 1 denotes a lift pin for moving a substrate G in a vertical direction.
It should be noted that, if the conventional heat treating unit 101 outlined above is used for applying a heat treatment to the wafer W having a coated film formed thereon, a substantially concentric thickness distribution is generated in the formed coated film as shown in FIG. 2 showing the film thickness distribution. Clearly, it is difficult to form a film having a uniform thickness over the entire wafer W.
An object of the present invention is to provide a substrate processing apparatus and a substrate processing method that permit forming a film having a uniform thickness over the entire substrate.
According to a first aspect of the present invention, there is provided a substrate processing apparatus, comprising:
holding means for holding a substrate substantially horizontal;
a chamber for applying a prescribed processing to the substrate held by said holding means;
a gas supply port formed through the upper wall of said chamber;
gas supply means for supplying a gas containing a prescribed vapor into said chamber through said gas supply port;
a diffusion plate arranged above the substrate held by said holding means within said chamber and having a plurality of gas spurting ports arranged at prescribed positions so as to permit the gas supplied into said chamber through said gas supply port to be supplied substantially uniformly onto the surface of said substrate; and
exhaust means for exhausting the gas supplied into said chamber to the outside through a bottom portion of said chamber.
In the substrate processing apparatus according to the first aspect of the present invention, a gas containing a prescribed vapor is supplied substantially uniformly onto the substrate so as to maintain constant the atmosphere around the substrate. As a result, it is possible to diminish the nonuniformity in the thickness and the characteristics of the formed film over the entire region of the substrate so as to make it possible to obtain a high quality substrate.
According to a second aspect of the present invention, there is provided a substrate processing apparatus, comprising:
holding means for holding a substrate substantially horizontal;
a chamber for applying a prescribed processing to the substrate held by said holding means and having a plurality of blocks;
a gas supply port and a gas exhaust port arranged in said chamber for every block;
gas supply means for supplying a gas containing a prescribed vapor into said chamber through said gas supply port;
gas exhausting means for exhausting said chamber through said gas exhaust port; and
a gas supply-exhaust control mechanism for optionally controlling for every block the gas supply into said chamber through said gas supply port and the exhaust of said chamber through said gas exhaust port.
According to a third aspect of the present invention, there is provided a substrate processing method for applying a prescribed processing to a substrate held under a prescribed gaseous atmosphere, comprising:
the step of housing a substrate in a chamber having a plurality of blocks and provided with a gas supply port and a gas exhaust port mounted for every block; and
the step of processing a substrate by optionally carrying out for every block a gas supply processing for supplying a gas containing a prescribed vapor into said chamber through said gas supply port and an exhaust processing within said chamber through said gas exhaust port.
In the substrate processing apparatus according to the second aspect of the present invention and in the substrate processing method according to the third aspect of the present invention, the supply-exhaust of a process gas into and out of the chamber housing the substrate can be carried out for every block. Therefore, it is possible to permit a part of the substrate to be exposed to the atmosphere differing from that of the other portion. As a result, it is possible to eliminate a partial thickness distribution so as to form a uniform film over the entire substrate. It follows that the present invention makes it possible to maintain a high quality of the substrate so as to improve the reliability.